Textiles are one of the fastest growing sectors of digital printing. The applications are numerous, with the most common including apparel, soft furnishing, soft signage and flags.
Also numerous is the choice of inks for inkjet printers. It’s not always clear what the difference is between some similarly-named fluids. Some have been adapted from earlier analogue printing processes, while others have only ever been available for inkjets.
The ‘hand feel’ of a textile is important, especially for clothing or garments (which we’re calling apparel here). This means the way the material flexes and drapes.
Dye inks enter the fibres of the textile and typically don’t alter the feel, though there may be an initial ink-acceptance coating that has to be washed out after printing. Inks that have a carrier that stays on the textile often make it stiffer and alter its feel.
Here we provide a brief introduction to the main types of inkjet textile inks, their characteristics and any pre- and post-processing needed to fix them. Some inks can also be used with leather, which isn’t a textile but is commonly used in apparel and furnishings.
We’ve not gone into detail with pre-treatments; this may be performed by the textile supplier, which will sell pre-treated materials for particular processes. Larger scale industrial printers may have the facilities to treat their own textiles.
Our thanks in particular to Steve Woodall, national sales manager for textiles and apparel at Hybrid Services, the UK distributor for Mimaki. He provided a lot of the practical information about these inks.
Note that dry toner printers can produce heat transfers suitable for textiles, but we’ll look at them another time.
Dye sublimation/disperse dye Textiles: polyester and polyester-cotton mix Pre-treatment: yes Process: inkjet onto paper or direct to textile rolls Post-process: dry heat/pressure transfer or dry heat activation and washing (direct printing) Application: apparel, soft furnishings, soft signage, flags, hard surfaces Dye sublimation is a water-based ink that works with a wide variety of inkjet printers. Most are adapted from standard eco-sol models, though a few have been purpose-built.
This ink is very widely used for textiles because it is easy to work with and only requires heat and a little pressure as a post-process.
It produces bright colours, but the limitation is that it only works with polyesters. Polyester-natural fibre mixes can be used, but the less polyester the fewer the binding points for the dye, so the image is duller and wash resistance suffers.
The ink can be used either to print onto a transfer paper or directly to the textile. Some manufacturers call it ‘disperse dye,’ usually when referring to direct printing. In some cases, the same ink is used for paper as direct to the textile (which needs a pre-treatment to reduce spread and wicking into the fibres before it is heat-fixed).